React UseDeferredValue

React useDeferredValue

Created By: chatGPT

useDeferredValue is a React hook that helps manage highly interactive user interfaces. It allows you to defer updates to a value until after the rendering of more urgent updates has completed. This is particularly useful for improving the perceived performance of your application when dealing with large datasets or slow computations.

import { useDeferredValue, useState } from 'react';

function SearchComponent() {
    const [searchTerm, setSearchTerm] = useState('');
    const deferredSearchTerm = useDeferredValue(searchTerm);

    // Simulate expensive rendering based on the search term
    const results = getSearchResults(deferredSearchTerm);

    return (
        <div>
            <input
                type="text"
                value={searchTerm}
                onChange={(e) => setSearchTerm(e.target.value)}
                placeholder="Search..."
            />
            <ul>
                {results.map(result => (
                    <li key={result.id}>{result.name}</li>
                ))}
            </ul>
        </div>
    );
}

function getSearchResults(term) {
    // Imagine this function performs a heavy search query
    return fakeDatabase.filter(item => item.name.includes(term));
}

const fakeDatabase = [
    { id: 1, name: 'Apple' },
    { id: 2, name: 'Banana' },
    { id: 3, name: 'Cherry' },
    { id: 4, name: 'Date' },
    { id: 5, name: 'Elderberry' }
];

In this example, when the user types in the input field, the searchTerm state updates immediately, but the rendering of results is deferred. This means that the rendering won't block other updates to the UI. Users can still interact with the rest of your application while the results are computed.

import { useDeferredValue, useState } from 'react';

function App() {
    const [value, setValue] = useState('');
    const deferredValue = useDeferredValue(value);

    return (
        <div>
            <input
                type="text"
                value={value}
                onChange={(e) => setValue(e.target.value)}
            />
            <p>Input: {value}</p>
            <p>Deferred Input: {deferredValue}</p>
        </div>
    );
}

Using useDeferredValue can significantly enhance user experience, especially in applications where rapid interactions and updates to the UI are essential. By separating the immediate state update from the rendering of potentially heavy computational results, you can create a more fluid and responsive interface.

function useImprovedPerformance() {
    const [data, setData] = useState([]);
    const deferredData = useDeferredValue(data);

    // Assume fetchData is a function that fetches data asynchronously
    useEffect(() => {
        fetchData().then(fetchedData => setData(fetchedData));
    }, []);

    return deferredData;
}